window.onload=function(){
	//获取对象
	let showBtn = document.getElementById('showBtn');
	let detailetBox = document.getElementById('detailetBox');
	
	//default hidden
	detailetBox.style.display = 'none';
	
	showBtn.onclick=function(){
		//if hidden, make it appears
		if(detailetBox.style.display == 'none'){
			detailetBox.style.display = 'block';
		}
		else{
			detailetBox.style.display = 'none';
		}
	}
	
}